1. Field of the Invention
The invention relates to a photoelectric composite wiring module which transmits signals through a conductive line and an optical fiber.
2. Description of the Related Art
A conventional photoelectric composite wiring module is known in which a flat cable having an optical transmission line and an electric wiring is optically and electrically connected to a pair of printed-circuit boards at both longitudinal ends (see JP-A-2011-53269).
In the photoelectric composite wiring module described in JP-A-2011-53269, an optical transmitter module composed of a light-emitting element and a driver IC is mounted on one of the paired printed-circuit boards and an optical receiver module composed of a light-receiving element and a preamplifier IC is mounted on another printed-circuit board.
A groove for the optical transmission line and a groove for the electric wiring are formed on one surface of each printed-circuit board. The groove for the optical transmission line receives an optical fiber as the optical transmission line protruding from an end portion of the flat cable, and the groove for the electric wiring receives the electric wiring protruding from the end portion of the flat cable. Meanwhile, the optical transmitter module or the optical receiver module is mounted on another surface of the printed-circuit board.
In addition, an optical waveguide is formed on the printed-circuit board so as to continue to the groove for the optical transmission line. A reflective portion is formed on the optical waveguide so as to reflect light emitted from the light-emitting element toward the optical fiber or light emitted from the optical fiber toward the light-receiving element. In addition, the reflective portion is formed on a surface of the printed-circuit board opposite to the surface mounting the light-emitting element or the light-receiving element so as to have a groove shape across the printed-circuit board. The light emitted from the light-emitting element or the optical fiber is reflected by the reflective portion and reaches the optical fiber or the light-emitting element after transmitting through the printed-circuit board.